def create_network(self, blocks):
models = nn.ModuleList()
prev_filters = 3
out_filters = []
prev_stride = 1
out_strides = []
conv_id = 0
for block in blocks:
if block['type'] == 'net':
prev_filters = int(block['channels'])
continue
elif block['type'] == 'convolutional':
conv_id = conv_id + 1
batch_normalize = int(block['batch_normalize'])
filters = int(block['filters'])
kernel_size = int(block['size'])
stride = int(block['stride'])
is_pad = int(block['pad'])
pad = (kernel_size - 1) // 2 if is_pad else 0
activation = block['activation']
model = nn.Sequential()
if batch_normalize:
model.add_module(
'conv{0}'.format(conv_id),
nn.Conv2d(prev_filters,
filters,
kernel_size,
stride,
pad,
bias=False))
model.add_module('bn{0}'.format(conv_id),
nn.BatchNorm2d(filters))
# model.add_module('bn{0}'.format(conv_id), BN2d(filters))
else:
model.add_module(
'conv{0}'.format(conv_id),
nn.Conv2d(prev_filters, filters, kernel_size, stride,
pad))
if activation == 'leaky':
model.add_module('leaky{0}'.format(conv_id),
nn.LeakyReLU(0.1, inplace=True))
elif activation == 'relu':
model.add_module('relu{0}'.format(conv_id),
nn.ReLU(inplace=True))
elif activation == 'mish':
model.add_module('mish{0}'.format(conv_id), Mish())
else:
print("convalution havn't activate {}".format(activation))
prev_filters = filters
out_filters.append(prev_filters)
prev_stride = stride * prev_stride
out_strides.append(prev_stride)
models.append(model)
elif block['type'] == 'maxpool':
pool_size = int(block['size'])
stride = int(block['stride'])
if stride == 1 and pool_size % 2:
# You can use Maxpooldark instead, here is convenient to convert onnx.
# Example: [maxpool] size=3 stride=1
model = nn.MaxPool2d(kernel_size=pool_size,
stride=stride,
padding=pool_size // 2)
elif stride == pool_size:
# You can use Maxpooldark instead, here is convenient to convert onnx.
# Example: [maxpool] size=2 stride=2
model = nn.MaxPool2d(kernel_size=pool_size,
stride=stride,
padding=0)
else:
model = MaxPoolDark(pool_size, stride)
out_filters.append(prev_filters)
prev_stride = stride * prev_stride
out_strides.append(prev_stride)
models.append(model)
elif block['type'] == 'avgpool':
model = GlobalAvgPool2d()
out_filters.append(prev_filters)
models.append(model)
elif block['type'] == 'softmax':
model = nn.Softmax()
out_strides.append(prev_stride)
out_filters.append(prev_filters)
models.append(model)
elif block['type'] == 'cost':
if block['_type'] == 'sse':
model = nn.MSELoss(size_average=True)
elif block['_type'] == 'L1':
model = nn.L1Loss(size_average=True)
elif block['_type'] == 'smooth':
model = nn.SmoothL1Loss(size_average=True)
out_filters.append(1)
out_strides.append(prev_stride)
models.append(model)
elif block['type'] == 'reorg':
stride = int(block['stride'])
prev_filters = stride * stride * prev_filters
out_filters.append(prev_filters)
prev_stride = prev_stride * stride
out_strides.append(prev_stride)
models.append(Reorg(stride))
elif block['type'] == 'upsample':
stride = int(block['stride'])
out_filters.append(prev_filters)
prev_stride = prev_stride // stride
out_strides.append(prev_stride)
models.append(Upsample_expand(stride))
# models.append(Upsample_interpolate(stride))
elif block['type'] == 'route':
layers = block['layers'].split(',')
ind = len(models)
layers = [
int(i) if int(i) > 0 else int(i) + ind for i in layers
]
if len(layers) == 1:
if 'groups' not in block.keys() or int(
block['groups']) == 1:
prev_filters = out_filters[layers[0]]
prev_stride = out_strides[layers[0]]
else:
prev_filters = out_filters[layers[0]] // int(
block['groups'])
prev_stride = out_strides[layers[0]] // int(
block['groups'])
elif len(layers) == 2:
assert (layers[0] == ind - 1 or layers[1] == ind - 1)
prev_filters = out_filters[layers[0]] + out_filters[
layers[1]]
prev_stride = out_strides[layers[0]]
elif len(layers) == 4:
assert (layers[0] == ind - 1)
prev_filters = out_filters[layers[0]] + out_filters[layers[1]] + out_filters[layers[2]] + \
out_filters[layers[3]]
prev_stride = out_strides[layers[0]]
else:
print("route error!!!")
out_filters.append(prev_filters)
out_strides.append(prev_stride)
models.append(EmptyModule())
elif block['type'] == 'shortcut':
ind = len(models)
prev_filters = out_filters[ind - 1]
out_filters.append(prev_filters)
prev_stride = out_strides[ind - 1]
out_strides.append(prev_stride)
models.append(EmptyModule())
elif block['type'] == 'connected':
filters = int(block['output'])
if block['activation'] == 'linear':
model = nn.Linear(prev_filters, filters)
elif block['activation'] == 'leaky':
model = nn.Sequential(nn.Linear(prev_filters, filters),
nn.LeakyReLU(0.1, inplace=True))
elif block['activation'] == 'relu':
model = nn.Sequential(nn.Linear(prev_filters, filters),
nn.ReLU(inplace=True))
prev_filters = filters
out_filters.append(prev_filters)
out_strides.append(prev_stride)
models.append(model)
elif block['type'] == 'region':
loss = RegionLoss()
anchors = block['anchors'].split(',')
loss.anchors = [float(i) for i in anchors]
loss.num_classes = int(block['classes'])
loss.num_anchors = int(block['num'])
loss.anchor_step = len(loss.anchors) // loss.num_anchors
loss.object_scale = float(block['object_scale'])
loss.noobject_scale = float(block['noobject_scale'])
loss.class_scale = float(block['class_scale'])
loss.coord_scale = float(block['coord_scale'])
out_filters.append(prev_filters)
out_strides.append(prev_stride)
models.append(loss)
elif block['type'] == 'yolo':
yolo_layer = YoloLayer()
anchors = block['anchors'].split(',')
anchor_mask = block['mask'].split(',')
yolo_layer.anchor_mask = [int(i) for i in anchor_mask]
yolo_layer.anchors = [float(i) for i in anchors]
yolo_layer.num_classes = int(block['classes'])
self.num_classes = yolo_layer.num_classes
yolo_layer.num_anchors = int(block['num'])
yolo_layer.anchor_step = len(
yolo_layer.anchors) // yolo_layer.num_anchors
yolo_layer.stride = prev_stride
yolo_layer.scale_x_y = float(block['scale_x_y'])
# yolo_layer.object_scale = float(block['object_scale'])
# yolo_layer.noobject_scale = float(block['noobject_scale'])
# yolo_layer.class_scale = float(block['class_scale'])
# yolo_layer.coord_scale = float(block['coord_scale'])
out_filters.append(prev_filters)
out_strides.append(prev_stride)
models.append(yolo_layer)
else:
print('unknown type %s' % (block['type']))
return models
def create_network(self, blocks):
"""根据 blocks 创建网络models
:param blocks: blocks模块配置
:return: nn.ModuleList()
"""
models = nn.ModuleList()
prev_filters = 3 # 前一层 channels个数
out_filters = [] # 所有层（无输入层）的通道数
prev_stride = 1 # 前一层 stride 大小，相对于原始图像大小
out_strides = [] # 所有层（无输入层）的stride大小，相对于原始图像大小
conv_id = 0 # 每一层ID
for block in blocks:
if block['type'] == 'net': # 网络配置
prev_filters = int(block['channels'])
continue
elif block['type'] == 'convolutional': # 卷积
conv_id = conv_id + 1
batch_normalize = int(block['batch_normalize'])
filters = int(block['filters'])
kernel_size = int(block['size'])
stride = int(block['stride'])
is_pad = int(block['pad'])
pad = (kernel_size - 1) // 2 if is_pad else 0
activation = block['activation']
model = nn.Sequential()
if batch_normalize:
model.add_module(
'conv{0}'.format(conv_id),
nn.Conv2d(prev_filters,
filters,
kernel_size,
stride,
pad,
bias=False))
model.add_module('bn{0}'.format(conv_id),
nn.BatchNorm2d(filters))
else:
model.add_module(
'conv{0}'.format(conv_id),
nn.Conv2d(prev_filters, filters, kernel_size, stride,
pad))
if activation == 'leaky':
model.add_module('leaky{0}'.format(conv_id),
nn.LeakyReLU(0.1, inplace=True))
elif activation == 'relu':
model.add_module('relu{0}'.format(conv_id),
nn.ReLU(inplace=True))
elif activation == 'mish':
model.add_module('mish{0}'.format(conv_id), Mish())
else:
print(
"Your activation is {}, but YOLO Layer ID {} convalution havn't activate {}"
.format(activation, conv_id, activation))
prev_filters = filters
out_filters.append(prev_filters)
prev_stride = stride * prev_stride
out_strides.append(prev_stride)
models.append(model)
elif block['type'] == 'maxpool': # maxpool
pool_size = int(block['size'])
stride = int(block['stride'])
if stride == 1 and pool_size % 2: # stride为1，3，5，...
# You can use Maxpooldark instead, here is convenient to convert onnx.
# Example: [maxpool] size=3 stride=1
model = nn.MaxPool2d(kernel_size=pool_size,
stride=stride,
padding=pool_size // 2)
elif stride == pool_size:
# You can use Maxpooldark instead, here is convenient to convert onnx.
# Example: [maxpool] size=2 stride=2
model = nn.MaxPool2d(kernel_size=pool_size,
stride=stride,
padding=0)
else:
model = MaxPoolDark(pool_size, stride)
out_filters.append(prev_filters)
prev_stride = stride * prev_stride
out_strides.append(prev_stride)
models.append(model)
elif block['type'] == 'avgpool':
model = GlobalAvgPool2d()
out_filters.append(prev_filters)
models.append(model)
elif block['type'] == 'softmax':
model = nn.Softmax()
out_strides.append(prev_stride)
out_filters.append(prev_filters)
models.append(model)
elif block['type'] == 'cost':
if block['_type'] == 'sse':
model = nn.MSELoss(reduction='mean')
elif block['_type'] == 'L1':
model = nn.L1Loss(reduction='mean')
elif block['_type'] == 'smooth':
model = nn.SmoothL1Loss(reduction='mean')
out_filters.append(1)
out_strides.append(prev_stride)
models.append(model)
elif block['type'] == 'reorg':
stride = int(block['stride'])
prev_filters = stride * stride * prev_filters
out_filters.append(prev_filters)
prev_stride = prev_stride * stride
out_strides.append(prev_stride)
models.append(Reorg(stride))
elif block['type'] == 'upsample':
stride = int(block['stride'])
out_filters.append(prev_filters)
prev_stride = prev_stride // stride
out_strides.append(prev_stride)
models.append(Upsample_expand(stride)) # 上采样 方式1
# models.append(Upsample_interpolate(stride)) # 上采样 方式2
elif block['type'] == 'route':
layers = block['layers'].split(',') # -1， -7
ind = len(models)
layers = [
int(i) if int(i) > 0 else int(i) + ind for i in layers
] # 通过layers定位到整个网络的下标
if len(layers) == 1: # 一条路径
if 'groups' not in block.keys() or int(
block['groups']) == 1:
prev_filters = out_filters[layers[0]]
prev_stride = out_strides[layers[0]]
else:
prev_filters = out_filters[layers[0]] // int(
block['groups'])
prev_stride = out_strides[layers[0]] // int(
block['groups'])
elif len(layers) == 2: # 两条路径
assert (layers[0] == ind - 1 or layers[1] == ind - 1)
prev_filters = out_filters[layers[0]] + out_filters[
layers[1]]
prev_stride = out_strides[layers[0]]
elif len(layers) == 4: # 四条路径
assert (layers[0] == ind - 1)
prev_filters = out_filters[layers[0]] + out_filters[layers[1]] + out_filters[layers[2]] + \
out_filters[layers[3]]
prev_stride = out_strides[layers[0]]
else:
print("route error!!!")
out_filters.append(prev_filters)
out_strides.append(prev_stride)
models.append(EmptyModule())
elif block['type'] == 'shortcut':
ind = len(models)
prev_filters = out_filters[ind - 1]
out_filters.append(prev_filters)
prev_stride = out_strides[ind - 1]
out_strides.append(prev_stride)
models.append(EmptyModule())
elif block['type'] == 'connected':
filters = int(block['output'])
if block['activation'] == 'linear':
model = nn.Linear(prev_filters, filters)
elif block['activation'] == 'leaky':
model = nn.Sequential(nn.Linear(prev_filters, filters),
nn.LeakyReLU(0.1, inplace=True))
elif block['activation'] == 'relu':
model = nn.Sequential(nn.Linear(prev_filters, filters),
nn.ReLU(inplace=True))
prev_filters = filters
out_filters.append(prev_filters)
out_strides.append(prev_stride)
models.append(model)
elif block['type'] == 'region':
loss = RegionLoss()
anchors = block['anchors'].split(',')
loss.anchors = [float(i) for i in anchors]
loss.num_classes = int(block['classes'])
loss.num_anchors = int(block['num'])
loss.anchor_step = len(loss.anchors) // loss.num_anchors
loss.object_scale = float(block['object_scale'])
loss.noobject_scale = float(block['noobject_scale'])
loss.class_scale = float(block['class_scale'])
loss.coord_scale = float(block['coord_scale'])
out_filters.append(prev_filters)
out_strides.append(prev_stride)
models.append(loss)
elif block['type'] == 'yolo':
yolo_layer = YoloLayer()
anchors = block['anchors'].split(',') # all anchors
anchor_mask = block['mask'].split(',') # anchor mask
yolo_layer.anchor_mask = [
int(i) for i in anchor_mask
] # 当前yolo layer的 anchor mask eg.[0,1,2]
yolo_layer.anchors = [float(i) for i in anchors
] # 当前yolo layer的 anchors eg.[xx,xx,xx]
yolo_layer.num_classes = int(
block['classes']) # 当前yolo layer的 classes类别数 eg.80
self.num_classes = yolo_layer.num_classes # DarkNet 类别数 eg.80
yolo_layer.num_anchors = int(
block['num']) # 当前yolo layer的 所有的anchors数量 eg.9
yolo_layer.anchor_step = len(
yolo_layer.anchors
) // yolo_layer.num_anchors # 索引 anchor的步长 eg.18/9=2
yolo_layer.stride = prev_stride # 此yolo layer特征图相对于原图的步长
yolo_layer.scale_x_y = float(block['scale_x_y']) # xy比例
out_filters.append(prev_filters)
out_strides.append(prev_stride)
models.append(yolo_layer)
else:
print('unknown type %s' % (block['type']))
return models
def create_network(self, blocks):
models = nn.ModuleList() # 创建一个空的ModuleList
prev_filters = 3
out_filters = []
prev_stride = 1
out_strides = []
conv_id = 0
for block in blocks:
if block['type'] == 'net': # 只有一个net
prev_filters = int(block['channels']) # 3
continue
elif block['type'] == 'convolutional': # 卷积层，yolov4.cfg共有110个卷积层
conv_id = conv_id + 1 # 按顺序将卷积层编号，后面进行模块命名
# 得到该卷积层的各项参数
batch_normalize = int(block['batch_normalize'])
filters = int(block['filters'])
kernel_size = int(block['size'])
stride = int(block['stride'])
is_pad = int(block['pad'])
# darknet只有两种kernel_size，若kernel_size=1,则pad=0 若kernel_size=3,则pad=1
# 补充：output_size =1+ (input_size+2*padding-kernel_size)/stride
pad = (kernel_size - 1) // 2 if is_pad else 0
activation = block['activation']
model = nn.Sequential() # 创建一个空的Sequential
# 公式：卷积层=ConvBnAct，有个别卷积层没有BN，有的层没有激活（linear）
if batch_normalize:
# 有BN，不需要偏置
model.add_module(
'conv{0}'.format(conv_id),
nn.Conv2d(prev_filters,
filters,
kernel_size,
stride,
pad,
bias=False))
model.add_module('bn{0}'.format(conv_id),
nn.BatchNorm2d(filters))
# model.add_module('bn{0}'.format(conv_id), BN2d(filters))
else:
# 没有BN，需要偏置（nn.Conv2d中的bias默认为True）
model.add_module(
'conv{0}'.format(conv_id),
nn.Conv2d(prev_filters, filters, kernel_size, stride,
pad))
if activation == 'leaky':
# inplace表示原地操作，在原变量不存在分支的情况下是没问题的，可以节省内存
model.add_module('leaky{0}'.format(conv_id),
nn.LeakyReLU(0.1, inplace=True))
elif activation == 'relu':
# yolov4里没有用relu
model.add_module('relu{0}'.format(conv_id),
nn.ReLU(inplace=True))
elif activation == 'mish':
model.add_module('mish{0}'.format(conv_id), Mish())
else:
# yolov4里除了leaky和mish，就是linear，表示没有激活层
# 这个打印信息没用,改成空语句pass
# print("convolution haven't activate {}".format(activation))
pass
prev_filters = filters
out_filters.append(prev_filters)
prev_stride = stride * prev_stride
out_strides.append(prev_stride)
models.append(model)
elif block['type'] == 'maxpool': # 最大池化层，yolov4.cfg只有3个
# 池化层只有两个参数，核大小和步长
pool_size = int(block['size']) # yolov4三个最大池化层的步长分别为5,9,13
stride = int(block['stride'])
if stride == 1 and pool_size % 2:
# You can use Maxpooldark instead, here is convenient to convert onnx.
# Example: [maxpool] size=3 stride=1
model = nn.MaxPool2d(kernel_size=pool_size,
stride=stride,
padding=pool_size // 2)
elif stride == pool_size:
# You can use Maxpooldark instead, here is convenient to convert onnx.
# Example: [maxpool] size=2 stride=2
model = nn.MaxPool2d(kernel_size=pool_size,
stride=stride,
padding=0)
else:
# yolov4用的都是MaxPoolDark
model = MaxPoolDark(pool_size, stride)
out_filters.append(prev_filters)
prev_stride = stride * prev_stride
out_strides.append(prev_stride)
models.append(model)
elif block['type'] == 'avgpool': # yolov4.cfg里没有avgpool
model = GlobalAvgPool2d()
out_filters.append(prev_filters)
models.append(model)
elif block['type'] == 'softmax': # yolov4.cfg里没有softmax
model = nn.Softmax()
out_strides.append(prev_stride)
out_filters.append(prev_filters)
models.append(model)
elif block['type'] == 'cost': # yolov4.cfg里没有cost
if block['_type'] == 'sse':
model = nn.MSELoss(reduction='mean')
elif block['_type'] == 'L1':
model = nn.L1Loss(reduction='mean')
elif block['_type'] == 'smooth':
model = nn.SmoothL1Loss(reduction='mean')
out_filters.append(1)
out_strides.append(prev_stride)
models.append(model)
elif block['type'] == 'reorg': # yolov4.cfg里没有reorg
stride = int(block['stride'])
prev_filters = stride * stride * prev_filters
out_filters.append(prev_filters)
prev_stride = prev_stride * stride
out_strides.append(prev_stride)
models.append(Reorg(stride))
elif block['type'] == 'upsample': # yolov4.cfg里有两个upsample
stride = int(block['stride'])
out_filters.append(prev_filters)
prev_stride = prev_stride // stride
out_strides.append(prev_stride)
models.append(Upsample_expand(stride)) # Upsample_expand上采样
# models.append(Upsample_interpolate(stride))
elif block['type'] == 'route': # yolo中的一个特殊层，作用是路由和拼接
layers = block['layers'].split(',')
ind = len(models)
# 如果layers索引大于0，则代表层数，如果小于0，代表从当前层往前减
layers = [
int(i) if int(i) > 0 else int(i) + ind for i in layers
]
if len(layers) == 1: # 如果layers只有一个
if 'groups' not in block.keys() or int(
block['groups']) == 1: # 对于yolov4.cfg，为True
# 获取指定layer的核数量和步长
prev_filters = out_filters[layers[0]]
prev_stride = out_strides[layers[0]]
else:
prev_filters = out_filters[layers[0]] // int(
block['groups'])
prev_stride = out_strides[layers[0]] // int(
block['groups'])
elif len(layers) == 2: # 如果layer有两个
# 如果layer有两个，肯定有一个是-1
assert (layers[0] == ind - 1 or layers[1] == ind - 1)
# 核数量为两个层的核数量之和
prev_filters = out_filters[layers[0]] + out_filters[
layers[1]]
prev_stride = out_strides[layers[0]]
elif len(layers) == 4: # 如果layer有4个
# 如果layer有四个，肯定有一个是-1
assert (layers[0] == ind - 1)
# 核数量为四个层的核数量之和
prev_filters = out_filters[layers[0]] + out_filters[layers[1]] + out_filters[layers[2]] + \
out_filters[layers[3]]
prev_stride = out_strides[layers[0]]
else:
print("route error!!!")
# 设置虚空的核数量和步长，以及用于占位的空层
out_filters.append(prev_filters)
out_strides.append(prev_stride)
models.append(EmptyModule())
elif block['type'] == 'shortcut': # yolov4里有23个shortcut
ind = len(models)
# 设置虚空的核数量和步长，以及用于占位的空层
prev_filters = out_filters[ind - 1]
out_filters.append(prev_filters)
prev_stride = out_strides[ind - 1]
out_strides.append(prev_stride)
models.append(EmptyModule())
elif block['type'] == 'connected': # yolov4.cfg里没有connected
filters = int(block['output'])
if block['activation'] == 'linear':
model = nn.Linear(prev_filters, filters)
elif block['activation'] == 'leaky':
model = nn.Sequential(nn.Linear(prev_filters, filters),
nn.LeakyReLU(0.1, inplace=True))
elif block['activation'] == 'relu':
model = nn.Sequential(nn.Linear(prev_filters, filters),
nn.ReLU(inplace=True))
prev_filters = filters
out_filters.append(prev_filters)
out_strides.append(prev_stride)
models.append(model)
elif block['type'] == 'region': # yolov4.cfg里没有region
loss = RegionLoss()
anchors = block['anchors'].split(',')
loss.anchors = [float(i) for i in anchors]
loss.num_classes = int(block['classes'])
loss.num_anchors = int(block['num'])
loss.anchor_step = len(loss.anchors) // loss.num_anchors
loss.object_scale = float(block['object_scale'])
loss.noobject_scale = float(block['noobject_scale'])
loss.class_scale = float(block['class_scale'])
loss.coord_scale = float(block['coord_scale'])
out_filters.append(prev_filters)
out_strides.append(prev_stride)
models.append(loss)
elif block['type'] == 'yolo': # yolov4.cfg里有3个yolo
yolo_layer = YoloLayer()
anchors = block['anchors'].split(',')
anchor_mask = block['mask'].split(',')
yolo_layer.anchor_mask = [int(i) for i in anchor_mask]
yolo_layer.anchors = [float(i) for i in anchors]
yolo_layer.num_classes = int(block['classes'])
self.num_classes = yolo_layer.num_classes
yolo_layer.num_anchors = int(block['num'])
yolo_layer.anchor_step = len(
yolo_layer.anchors) // yolo_layer.num_anchors
yolo_layer.stride = prev_stride
yolo_layer.scale_x_y = float(block['scale_x_y'])
# yolo_layer.object_scale = float(block['object_scale'])
# yolo_layer.noobject_scale = float(block['noobject_scale'])
# yolo_layer.class_scale = float(block['class_scale'])
# yolo_layer.coord_scale = float(block['coord_scale'])
out_filters.append(prev_filters)
out_strides.append(prev_stride)
models.append(yolo_layer)
else:
print('unknown type %s' % (block['type']))
return models
def create_network(self, blocks):
"""
nn.ModuleList仅仅类似于pytho中的list类型，只是将一系列层装入列表，并没有实现forward()方法，因此也不会有网络模型产生的副作用，
但它有和纯python中的list不同，用nn.ModuleList或者ParameterList包裹模型各个层之后，我们不光可以像python里的list一样对模型的各个层进行索引，
同时这些层的参数将会被自动注册，这些层的参数只有被正确注册之后，优化器才能发现和训练这些参数
这个操作只会生成一个空的list
"""
models = nn.ModuleList()
prev_filters = 3
out_filters = []
prev_stride = 1
out_strides = []
conv_id = 0
for block in blocks: # 遍历 blocks 的时候，模型不断累加到一起
if block['type'] == 'net': #网络参数
prev_filters = int(block['channels']) #第一次的卷积核个数就是看看有多少个通道
continue # 一共就一个net参数表
elif block['type'] == 'convolutional': #卷积层
conv_id = conv_id + 1
# 数据经过多层神经网络后,数据分布发生变化,导致各层参数需要不到调整适应分布变化,这会让收敛速度变慢,
# 超参数设定也变得比较复杂,这在论文里作者称作Internal Covariate Shift
# batch_normalize 用于防止梯度消失，就是将后面的数据分布进行规整，
batch_normalize = int(block['batch_normalize']) # always 1, 除了最后的输出层，每一层都是用了 batch_normalize
filters = int(block['filters']) # 卷积核，其实就是滤波器。在每次迭代中会进行更新参数
kernel_size = int(block['size'])
stride = int(block['stride']) # 步长
is_pad = int(block['pad']) # padding 过程 这里的padding 始终=1，仅用于表示：需要 padding
pad = (kernel_size - 1) // 2 if is_pad else 0 # padding 大小
activation = block['activation'] # 激活层，激活函数是用来加入非线性因素的，因为线性模型的表达能力不够。
model = nn.Sequential() # 模型为空，通过add_module添加模型结构
if batch_normalize:
# add_module(self, name, module)
# nn.Conv2d(self, in_channels, out_channels, kernel_size, stride=1,
# padding=0, dilation=1, groups=1,
# bias=True, padding_mode='zeros')
model.add_module('conv{0}'.format(conv_id),
nn.Conv2d(prev_filters, filters, kernel_size, stride, pad, bias=False))
# print('create_network: conv{0}'.format(conv_id))
# 块标准化的目的就是让传输的数据合理的分布，加速训练的过程
model.add_module('bn{0}'.format(conv_id), nn.BatchNorm2d(filters))
# model.add_module('bn{0}'.format(conv_id), BN2d(filters))
else:
model.add_module('conv{0}'.format(conv_id),
nn.Conv2d(prev_filters, filters, kernel_size, stride, pad))
if activation == 'leaky':
model.add_module('leaky{0}'.format(conv_id), nn.LeakyReLU(0.1, inplace=True))
elif activation == 'relu':
model.add_module('relu{0}'.format(conv_id), nn.ReLU(inplace=True))
elif activation == 'mish':
model.add_module('mish{0}'.format(conv_id), Mish())
else:
print(conv_id,"convalution havn't activate {}".format(activation))
prev_filters = filters
out_filters.append(prev_filters)
prev_stride = stride * prev_stride
out_strides.append(prev_stride)
models.append(model)
elif block['type'] == 'maxpool':
pool_size = int(block['size'])
stride = int(block['stride'])
if stride == 1 and pool_size % 2:
# You can use Maxpooldark instead, here is convenient to convert onnx.
# Example: [maxpool] size=3 stride=1
model = nn.MaxPool2d(kernel_size=pool_size, stride=stride, padding=pool_size // 2)
elif stride == pool_size:
# You can use Maxpooldark instead, here is convenient to convert onnx.
# Example: [maxpool] size=2 stride=2
model = nn.MaxPool2d(kernel_size=pool_size, stride=stride, padding=0)
else:
model = MaxPoolDark(pool_size, stride)
out_filters.append(prev_filters)
prev_stride = stride * prev_stride
out_strides.append(prev_stride)
models.append(model)
elif block['type'] == 'avgpool':
model = GlobalAvgPool2d()
out_filters.append(prev_filters)
models.append(model)
elif block['type'] == 'softmax':
model = nn.Softmax()
out_strides.append(prev_stride)
out_filters.append(prev_filters)
models.append(model)
elif block['type'] == 'cost':
if block['_type'] == 'sse':
model = nn.MSELoss(reduction='mean')
elif block['_type'] == 'L1':
model = nn.L1Loss(reduction='mean')
elif block['_type'] == 'smooth':
model = nn.SmoothL1Loss(reduction='mean')
out_filters.append(1)
out_strides.append(prev_stride)
models.append(model)
elif block['type'] == 'reorg':
stride = int(block['stride'])
prev_filters = stride * stride * prev_filters
out_filters.append(prev_filters)
prev_stride = prev_stride * stride
out_strides.append(prev_stride)
models.append(Reorg(stride))
elif block['type'] == 'upsample':
stride = int(block['stride'])
out_filters.append(prev_filters)
prev_stride = prev_stride // stride
out_strides.append(prev_stride)
models.append(Upsample_expand(stride))
# models.append(Upsample_interpolate(stride))
elif block['type'] == 'route':
layers = block['layers'].split(',')
ind = len(models)
layers = [int(i) if int(i) > 0 else int(i) + ind for i in layers]
if len(layers) == 1:
if 'groups' not in block.keys() or int(block['groups']) == 1:
prev_filters = out_filters[layers[0]]
prev_stride = out_strides[layers[0]]
else:
prev_filters = out_filters[layers[0]] // int(block['groups'])
prev_stride = out_strides[layers[0]] // int(block['groups'])
elif len(layers) == 2:
assert (layers[0] == ind - 1 or layers[1] == ind - 1)
prev_filters = out_filters[layers[0]] + out_filters[layers[1]]
prev_stride = out_strides[layers[0]]
elif len(layers) == 4:
assert (layers[0] == ind - 1)
prev_filters = out_filters[layers[0]] + out_filters[layers[1]] + out_filters[layers[2]] + \
out_filters[layers[3]]
prev_stride = out_strides[layers[0]]
else:
print("route error!!!")
out_filters.append(prev_filters)
out_strides.append(prev_stride)
models.append(EmptyModule())
elif block['type'] == 'shortcut':
ind = len(models)
prev_filters = out_filters[ind - 1]
out_filters.append(prev_filters)
prev_stride = out_strides[ind - 1]
out_strides.append(prev_stride)
models.append(EmptyModule())
elif block['type'] == 'connected':
filters = int(block['output'])
if block['activation'] == 'linear':
model = nn.Linear(prev_filters, filters)
elif block['activation'] == 'leaky':
model = nn.Sequential(
nn.Linear(prev_filters, filters),
nn.LeakyReLU(0.1, inplace=True))
elif block['activation'] == 'relu':
model = nn.Sequential(
nn.Linear(prev_filters, filters),
nn.ReLU(inplace=True))
prev_filters = filters
out_filters.append(prev_filters)
out_strides.append(prev_stride)
models.append(model)
elif block['type'] == 'region':
loss = RegionLoss()
anchors = block['anchors'].split(',')
loss.anchors = [float(i) for i in anchors]
loss.num_classes = int(block['classes'])
loss.num_anchors = int(block['num'])
loss.anchor_step = len(loss.anchors) // loss.num_anchors
loss.object_scale = float(block['object_scale'])
loss.noobject_scale = float(block['noobject_scale'])
loss.class_scale = float(block['class_scale'])
loss.coord_scale = float(block['coord_scale'])
out_filters.append(prev_filters)
out_strides.append(prev_stride)
models.append(loss)
elif block['type'] == 'yolo':
yolo_layer = YoloLayer()
anchors = block['anchors'].split(',')
anchor_mask = block['mask'].split(',')
yolo_layer.anchor_mask = [int(i) for i in anchor_mask]
yolo_layer.anchors = [float(i) for i in anchors]
yolo_layer.num_classes = int(block['classes'])
self.num_classes = yolo_layer.num_classes
yolo_layer.num_anchors = int(block['num'])
yolo_layer.anchor_step = len(yolo_layer.anchors) // yolo_layer.num_anchors
yolo_layer.stride = prev_stride
yolo_layer.scale_x_y = float(block['scale_x_y'])
# yolo_layer.object_scale = float(block['object_scale'])
# yolo_layer.noobject_scale = float(block['noobject_scale'])
# yolo_layer.class_scale = float(block['class_scale'])
# yolo_layer.coord_scale = float(block['coord_scale'])
out_filters.append(prev_filters)
out_strides.append(prev_stride)
models.append(yolo_layer)
else:
print('unknown type %s' % (block['type']))
return models